Preliminary investigation of dry tribochemical mechanical polishing of single crystal SiC substrates

Aiming at the issues of low efficiency, high cost, and environmental pollution associated with silicon carbide (SiC) substrates in the polishing process, a method of tribochemical mechanical polishing of SiC substrates in the dry state (Dry Tribochemical Mechanical Polishing, DTCMP) is proposed. The effect of different process parameters (abrasive type, abrasive size, abrasive content, polishing plate speed, polishing load, solid phase oxidant content) on the polishing efficiency and surface quality of single-crystal silicon carbide substrates was investigated. The results show that diamond abrasive is more suitable for the tribochemical mechanical polishing of silicon carbide. Optimal test parameters are achieved when the abrasive size is W1, the abrasive content is 4 g, the polishing plate speed is 70 r/min, the polishing load is 20.685 kPa, and the solid phase oxidant sodium percarbonate is added at 10 g. Single-crystal 6H-SiC substrates with a surface roughness of approximately 20 nm were polished using the optimal process parameters, finanlly resulting in a surface roughness of R_a of 3.214 nm. The DTCMP method for polishing SiC substrate has less heat loss than water-based polishing method, enabling higher interface temperature and lower activation energy required for reactions. This method can realize green, efficient and high-quality polishing of SiC substrates.